Renesas HZU4.3B3TRF-E

Overview

HZU4.3B3TRF-E from Renesas Electronics is a silicon planar Zener diode designed for precision voltage stabilization in low-power analog and digital supply rails, featuring a nominal Zener voltage of 4.3 V (±0.1 V tolerance), 200 mW power dissipation, and ultra-small URP (SC-76A) surface-mount package. It operates with 5 mA test current, exhibits 130 Ω dynamic resistance, and supports cathode-anode polarity marking for unambiguous PCB layout in compact DC-DC feedback paths and reference circuits.

For engineers reviewing the HZU4.3B3TRF-E datasheet, HZU4.3B3TRF-E pinout, HZU4.3B3TRF-E application, or HZU4.3B3TRF-E equivalent, key selection criteria include its B3-grade voltage accuracy (4.28–4.48 V), low reverse leakage (<10 µA at 1.0 V), thermal stability up to 150°C junction temperature, and compatibility with automated SMT assembly due to TRF taping (3,000 pcs/reel).

Technical Context

This Zener diode uses a silicon planar junction structure optimized for stable reverse-breakdown operation under DC bias. Its electrical behavior is defined by tight Zener voltage grading (B3), low dynamic impedance (130 Ω at 5 mA), and specified reverse current limits (≤10 µA at VR = 1.0 V), enabling reliable regulation in low-current sensing and reference applications.

The device is rated for 200 mW power dissipation at 25°C ambient, derating linearly above 25°C per Fig.3, and supports storage temperatures from –55°C to +150°C. Its URP package (0.8 mm × 1.5 mm footprint, 0.45 mm height) ensures minimal board area usage while maintaining thermal performance suitable for space-constrained consumer and industrial electronics.

Key Specifications

Pinout & Package

Ultra-small Resin Package (URP, JEITA code SC-76A) measures 0.8 mm × 1.5 mm × 0.45 mm (L × W × H), with cathode marked on top surface. The two-terminal device has no internal circuitry beyond the Zener junction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener diode voltage stabilization applications.

Compared with BZX384-B4V3,115 and MMSZ4V3ET1G, the HZU4.3B3TRF-E offers tighter B3-grade voltage control (±0.1 V vs. ±5%), smaller URP footprint (0.8 × 1.5 mm vs. 1.7 × 1.3 mm), and lower dynamic resistance - making it optimal for precision, space-limited reference and biasing roles.

Availability

HZU4.3B3TRF-E is available at Aetrix Electronics and suitable for precision voltage reference, sensor biasing, microcontroller reset generation, and overvoltage protection applications requiring stable component supply and consistent B3-grade parametric performance.

Supply support for HZU4.3B3TRF-E includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Renesas Electronics is a global semiconductor manufacturer headquartered in Japan, specializing in microcontrollers, analog and power devices, and system-on-chip solutions for industrial, automotive, and consumer markets.

The HZU Series is part of Renesas' discrete Zener diode portfolio, engineered specifically for high-accuracy, low-power voltage stabilization in compact surface-mount applications where grade-specific tolerance and thermal robustness are critical.

FAQ

What is the Zener voltage tolerance of HZU4.3B3TRF-E?

The HZU4.3B3TRF-E has a Zener voltage range of 4.28 V to 4.48 V at 5 mA test current, corresponding to the B3 grade specification. This ±0.1 V tolerance provides tighter regulation than standard B, B1, or B2 grades and is confirmed in the Electrical Characteristics table on page 2 of the R07DS0423EJ1000 datasheet. The HZU4.3B3TRF-E is therefore suitable for applications demanding high reference accuracy without trimming.

Does HZU4.3B3TRF-E support automated SMT assembly?

Yes, the HZU4.3B3TRF-E is supplied in TRF taping format (3,000 pieces per reel), fully compatible with standard pick-and-place equipment. Its URP (SC-76A) package dimensions - 0.8 mm × 1.5 mm body with 0.45 mm height - align with IPC-7351 guidelines for ultra-small passive components. The HZU4.3B3TRF-E's cathode marking and consistent terminal geometry further ensure reliable vision-based placement and solder joint formation.

What is the maximum reverse leakage current for HZU4.3B3TRF-E?

The HZU4.3B3TRF-E specifies a maximum reverse current (I_R) of 10 µA at V_R = 1.0 V, as stated in the Electrical Characteristics table. This low leakage supports high-impedance bias networks and minimizes error in precision reference dividers. The value is measured under controlled conditions (T_a = 25°C) and remains stable across the –55°C to +150°C storage temperature range, confirming the HZU4.3B3TRF-E's suitability for low-power always-on circuits.

Can HZU4.3B3TRF-E replace older Zener diodes like 1N4733A?

No, the HZU4.3B3TRF-E is not a direct replacement for through-hole diodes such as 1N4733A due to fundamental differences in package (URP vs. DO-41), power rating (200 mW vs. 1 W), and voltage tolerance (±0.1 V vs. ±5%). While both regulate near 4.3 V, the HZU4.3B3TRF-E targets surface-mount, low-power precision roles, whereas 1N4733A serves higher-power, through-hole applications. Substitution requires layout redesign and verification of thermal and regulation performance in the HZU4.3B3TRF-E's operating range.

What is the thermal derating behavior of HZU4.3B3TRF-E above 25°C?

The HZU4.3B3TRF-E follows linear thermal derating above 25°C ambient, as shown in Fig.3 of the datasheet: power dissipation decreases from 200 mW at 25°C to zero at approximately 125°C. The slope is ~2.5 mW/°C, meaning at 75°C ambient, the usable P_d is reduced to 75 mW. This behavior is intrinsic to the URP package's thermal resistance and must be accounted for in sustained high-temperature deployments of the HZU4.3B3TRF-E.